Introduction - new HP15C owner

[carey]

(10-05-2023 08:47 PM)Johnh Wrote:  I don't think it'll [HP39gii] get much use from me, but is it worth investigating further to understand it?

A few strengths of the HP39gii (and HP Prime) are:
1) An adaptive plotting algorithm that plots more points where functions change rapidly, resulting in more accurate and higher-resolution plots.
2) A structured programming language with similarities to Modula-2 (another Wirth language that evolved from Pascal). Functions can be defined that behave as 1st class objects (i.e., as if built-in) though slower.
3) Similar UI and functionality as the older 38/39 series (38g, 39g, 39g+, 39gs), an advantage, of course, if already familiar with these models or if the idea of Applets (mathematical environments with integrated numeric, symbolic, and plotting capabilities for doing and exploring math) is attractive.
4) Speedy operation. The 38gii clock speed (around 80 MHZ) is similar to the 39gs, however, the latter emulates a Saturn processor, while the 38gii runs without an emulation speed penalty on a platform-independent C codebase.
5) Unicode characters and improved unit capabilities.

Alas, before the many programmer months and additional ROM update cycles that would have been needed for a more stable 39gii, the particular Freescale chip it used went out of production. While still quite a usable calculator, freezing and resetting are not rare, which gives the calculator the feel of a work-in-progress, even after its last ROM update. This is not surprising considering that the 39gii required writing platform-independent C code from scratch rather than emulating previous HP calculator processors. I recall seeing several useful MoHPC posts that offer various key combinations to try in cases of freezing.